Face masks are worn in medical environments, such as surgical operating rooms, in order to minimize the transfer of contaminants. In an operating room, the surgeons, nurses, and other personnel wear face masks so as to filter out contaminants from their breathing and to minimize the risk of infection to the patient undergoing the surgical procedure. In addition, the face masks serve to protect the medical personnel from infectious agents that may emanate from the patient.
Another use for face masks is in clean rooms. Such clean rooms are used, for example, in semiconductor manufacturing. The face masks reduce particle emissions from the human workers.
Early face masks were made of cloth and were sewn together. In the 1960's, masks began to be made from disposable non-woven fabrics. At first, the disposable fabrics were sewn; later the masks were made by ultrasonically bonding the materials to each other.
One general type of face mask is flat and is typically rectangular in shape. Flat face masks are typically pleated in the mask body to allow for some fitting of the mask to the curvature of a human face. A flat face mask can be of the 4-tie variety or the ear loop variety. In the 4-tie variety, ties extend out from the mask body which are then tied around the back of the wearer's head. The ear loop variety has elastic loops that fit around the ears of the wearer; no tying is needed.
The prior art flat face mask has a flat nose strip along the top edge. To use, the face mask is placed against the face, with the nose strip located on the bridge of the nose. The user presses the nose strip to form a contour around the nose.
Another type or style of face mask is the “cone” or “cup-shaped” mask, which is a molded bowl-shaped mask with an elastic band that extends around the back of a wearer's head. Such cone masks are described in U.S. Pat. Nos. 4,807,619 and 4,536,440. They have a shaping layer of thermally bonded fibers, which layer provides the cone shape. The shaping layer is made by molding webs of thermally bonding fibers in heated molds, which molds are at temperatures above the softening point of the thermally bonding fibers.
Flat face masks typically have a body with three layers, namely an outer layer, a middle filtration layer and an inner layer. The inner layer is chosen so as to be comfortable on the skin. The outer layer can irritate the skin. Therefore, it is desirable to properly orient the mask to the skin, so that the inner layer is against the skin. In addition, the face mask typically has a fluid resistant layer and has an anti-microbial layer. These fluid resistant masks and anti-microbial masks perform satisfactorily only if they are worn correctly, with the outer layer on the outside and the inside layer against the wearer.
Identifying the proper orientation of a flat face mask has proven difficult. People frequently don a flat face mask with the inner layer facing out, in an inside out orientation.
In many masks, the inner and outer layers are the same color, making identification of the inside particularly difficult. In some prior art flat face masks, the inner layer and outer layer are different colors. Even with this color differentiation however, problems persist in correctly donning the face mask. Furthermore, some prior art face masks have the word “inside” imprinted on the inner layer. However, health care workers still don the masks inside out.